Add new empty debug function.

compiler/debug.py

@@ -107,3 +107,18 @@ def info(lev, str):
             class_name = mod.__name__
         print_raw("[{0}/{1}]: {2}".format(class_name,
                                           frm[0].f_code.co_name, str))
+
+
+def bp():
+    """
+    An empty function so you can set soft breakpoints in pdb.
+    Usage:
+    1) Add a breakpoint anywhere in your code with "import debug; debug.bp()".
+    2) Run "python3 -m pdb openram.py config.py" or "python3 -m pdb 05_bitcell_array.test" (for example)
+    3) When pdb starts, run "break debug.py" to set a SOFT breakpoint. (Or you can add this to your ~/.pdbrc)
+    4) Then run "cont" to continue.
+    5) You can now set additional breakpoints or display commands 
+    and whenever you encounter the debug.bp() they won't be "reset".
+    """
+    pass
+